Embodiments are directed to methods and systems for evaluating the solid particle separation of wellbore fluids, and more particularly, embodiments disclose using turbidimetry to measure the separation of solids from wellbore fluids as the wellbore fluids flow across a permeable obstruction, such as porous media and fractured media.
Solid removal processes and solids control systems may be an important aspect of wellbore fluid treatment. For example, the removal of solids from drilling fluids may be important to maintain the integrity of the fluid. If solids are not sufficiently removed from the drilling fluid, the amount of drilling fluid that may be reused may be reduced, resulting in additional operations expenditures. Further, higher than normal concentrations of solids in wellbore fluids may require additional amounts of said wellbore fluids to dilute the solids so that they do not impact wellbore operations. The need for additional amounts of wellbore fluids may also result in additional operations expenditures. Additionally, wellbore fluids may be lost to lost circulation zones, also known as thief zones, in the subterranean formation. If a lost circulation zone is not successfully bridged, wellbore fluid may be lost, pressure may be lost, and the formation could potentially be damaged. Finally, in operations using hydraulic fracturing, the choice of proppant can impact the effectiveness of the fracturing operation. Choosing a proppant that is incapable of build-up within a fracture or is incapable of propping a fracture may result in the fracture closing, thereby causing a loss in the recovery of valuable hydrocarbons from the fracture.
Generally the removal of solids or the loss of fluid may be measured through the monitoring of the pressure-flow characteristics of the wellbore fluid. However, this evaluation requires input parameters by calibration and calculation and cannot be used to measure the dynamic separation process. In the case of testing the effectiveness of bridging lost circulation zones, American Petroleum Institute Recommended Practice 13B-1 Annex J and/or 13B-2 Annex L may be used. However, these practices may be limited in scope in that they do typically not allow for analysis of the dynamics of particle build-up within and above the lost circulation zone. Similarly to the measurement of the effectiveness of lost circulation materials, current applications for testing the effectiveness of proppant build-up in a fracture also may not allow for analysis of the dynamics of particle build-up within the fracture.